Tsukasa is the younger fraternal twin sister of Kagami and lives in a six-member family household with her parents. She isn't good at studying or at sports but excels in cooking. Tsukasa is also in the same class as Konata.

Tsukasa's physique is a little smaller than average. She has short, light-purple hair, and wears a ribbon like a head band in it, and her droopy eyes are light violet. She is portrayed as a stereotypical klutz and as a "healing-type" character. She spends a lot of time sleeping.